[James Romeyn]

I respectfully request someone with an Atmos receiver confirm whether or not it allows Atmos on the front speakers only.  I presume it does not, and rather requires front and rear or none.   

What's the general consensus on consumer Atmos?  AVS editors visited 2014 CEDIA.  In the Dolby Atmos demo they directly AB compared Atmos speakers in-ceiling vs. up-firing.  The editors who had a preference and shared such preferred the up-firing because it was less directional.   

[jarcher]

 You can do Atmos on the front only.   General consensus is that front and rear together is much better and that in ceiling vs up firing is much better.  I've heard an Atmos demos with all pioneer elite gear with just front up firing and the effect was pretty much limited to the front pane. I later installed an all pioneer elite atmos system (one with Andrew Jones elite speakers) for front and rear and the effect was impressive with the sonic bubble better covering the whole sphere between in front and behind me. For example, in the John Wick movie scene in the cemetery when it's raining hard, it feels like you are in the middle of it all with rain coming down all around you. It helped that the ceiling was bare drywall and at optimum height. And per the Sound and Vision article about that whole Pioneer Elite system when Andrew Jones himself set it up, I also jacked up manually the Atmos speaker levels 3db post running the automated room correction software.

Sound and Vision magazine has a very good articles about the different implementations of Atmos based on their experiments running different configurations which I think addresses many of your questions.  Check. Out at :

http://www.soundandvision.com/content/dolby-atmos-vs-dolby-atmos#azHSzXeY2SLyok00.97

[James Romeyn]

Great link, thanks very much.

Atmos speakers require bass cutoff of only 180 Hz, which Dolby defines as "full range."  Per Wiki, the piano key closest in pitch is 184.997 Hz, 34th from the left, F sharp 3 or G flat 3: https://en.wikipedia.org/wiki/Piano_key_frequencies  The sum total of audible octaves is about ten, a little over three of them (30%+) below 180 Hz.  I estimate a laptop computer speaker with below average bass cuts off around 125 Hz.  I wonder the ratio of audiophiles who agree with Dolby's definition?